Hesitation
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New User
Joined: May 2004
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From: Upstate NY
Hesitation
Hi, I have 2002 Expedition 4.6L that I bought 2 1/2 years ago. It's run like a champ and now has about 82k miles on it.
I've recently noticed a hesitation while cruising at about 50 mph, which is now getting worse. It occurs only when I'm riding at low rpm, presumably in the highest gear. If I hit 50mph at a lower gear, and rpm, it does not happen. But if I let off the gas, and allow it to shift up, it will then happen.
I don't get any check engine light. I've never actually gotten one since I brought it to the dealer a year ago for some service, and they neglected to reattach the pcv hose.
Anybody ever run into this problem? Thanks!
I've recently noticed a hesitation while cruising at about 50 mph, which is now getting worse. It occurs only when I'm riding at low rpm, presumably in the highest gear. If I hit 50mph at a lower gear, and rpm, it does not happen. But if I let off the gas, and allow it to shift up, it will then happen.
I don't get any check engine light. I've never actually gotten one since I brought it to the dealer a year ago for some service, and they neglected to reattach the pcv hose.
Anybody ever run into this problem? Thanks!
Freshman User
Joined: Jul 2006
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I had the same problem last year and after taking it to the dealer found out it was a bad COP. I was surprised that it had not thrown a code but as stated above it might not be gone far enough for that to happpen yet.
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New User
Joined: May 2004
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From: Upstate NY
Thanks for the replies. The plugs have not been changed during the time I've owned the truck, so I can do the wires and plugs easily enough this weekend, and post my results. If that doesn't work out, how does one go about troubleshooting the COPS? Thanks!
Senior User
Joined: Jan 2005
Posts: 196
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From: Franklin, NC
Go to autozone or some place of the sort and buy just one ignition coil. Plug that one new one in each of the eight cylinders and see which one fixes the problem. When the problem starts to act up, give your truck a little more gas and try to throw a code. I have been through this several times and the ignition coils are a pretty safe bet on these trucks.
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From: Upstate NY
OK, thanks for that, I can certainly go to one of those places nearby and grab a single coil, and give it a shot. So far, I haven't been able to throw a code, but maybe I'll get lucky on the highway. So, with 82k miles, I'll probably replace with Motorcraft plugs after this COP troubleshooting. I also like the suggestion of replacing the fuel filter, I checked my Haynes book and it says to do so every year anyway, so I'm definitely behind on that. Now for some fuel line disconnect fun baby!! :O
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New User
Joined: May 2004
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From: Upstate NY
OK IT'S FIXED
I went and bought some plugs, and a fuel filter. The first thing I tried was checking the coils. I removed each one, inspected the boot for cracks, and tested the primary and secondary resistance per the haynes manual. In the manual it says that the primary resistance should be between .3 and 1.0 ohms, each one checked out OK in this range.
For the secondary resistance, the manual states the resistance should be between 6.5 and 11.5 K-ohms. For all 8 of my coils this was not the case, they all measured at about 5.8 K-ohms.
I then reinstalled all the coils with dielectric grease on all connection points. I took it for a test drive, and there was no change, it still hesitated pretty badly.
I decided against doing the plugs, and instead replaced the fuel filter. After struggling with the disconnect tool, and getting gasoline in my ear (HOLY CRAP THAT HURTS!!) I put on a new Motorcraft filter. I took it for a test drive, AND THAT WAS IT!!
A NINE DOLLAR PART!! The haynes manual advises changing it yearly, and I definitely agree, good call Freak4Ford. Thanks again for all the replies.
I went and bought some plugs, and a fuel filter. The first thing I tried was checking the coils. I removed each one, inspected the boot for cracks, and tested the primary and secondary resistance per the haynes manual. In the manual it says that the primary resistance should be between .3 and 1.0 ohms, each one checked out OK in this range.
For the secondary resistance, the manual states the resistance should be between 6.5 and 11.5 K-ohms. For all 8 of my coils this was not the case, they all measured at about 5.8 K-ohms.
I then reinstalled all the coils with dielectric grease on all connection points. I took it for a test drive, and there was no change, it still hesitated pretty badly.
I decided against doing the plugs, and instead replaced the fuel filter. After struggling with the disconnect tool, and getting gasoline in my ear (HOLY CRAP THAT HURTS!!) I put on a new Motorcraft filter. I took it for a test drive, AND THAT WAS IT!!
A NINE DOLLAR PART!! The haynes manual advises changing it yearly, and I definitely agree, good call Freak4Ford. Thanks again for all the replies.
